There has been known a problem relating to increase in the amount of heat generated from heat sources in PCs (personal computers) such as ICs (Integrated Circuit), owing to the increase in performance of PCs. A known method for dissipating the heat involves bringing the IC in contact with radiating fins formed of a metal such as aluminum or the like, for example, so as to dissipate the heat from the IC by head conduction though the radiating fins. There is also a method known wherein a fan is used to forcibly displace warmed air within the PC housing and introduce the cooler ambient air, thereby dissipating heat. There is further a method known wherein both the radiating fins and fan are used together, whereby the area of contact between the heat source and the air is increased by way of the radiating fins, and the warmed air around the radiating fins is forcibly displaced by the fan.
However, with such forced convention of air with a fan, a thermal boundary layer occurs at the surface of the radiating fins on the downstream side, meaning there is a problem that heat cannot be efficiently conducted away from the radiating fins. One way to deal with this problem is to increase the airflow speed from the fan for example, so as to reduce the thickness of the thermal boundary layer. However, increasing the number of revolutions in order to increase the airflow speed leads to problems of noise from the fan bearings, noise due to wind roar, and so forth.
On the other hand, there is known a method wherein instead of a fan serving as a blower, a vibrating plate is used which cyclically performs reciprocal actions to disrupt the thermal boundary layer and efficiently release the heat from the radiating fins into the ambient atmosphere (e.g., see Patent Documents 1, 2, 3, 4). Of these, the devices in Patent Documents 3 and 4 in particular have a vibrating plate which generally divides a chamber into two spatially, an elastic member provided in the chamber so as to support the vibrating plate, and means for vibrating the vibrating plate. With such a device, when the vibrating plate is displaced upwards for example, the volume of the upper space in the chamber is reduced, so the pressure in the upper space rises. The upper space communicates with the ambient atmosphere via a vent, and accordingly a part of the air within the upper space is externally discharged. On the other hand, the volume of the lower space on the other side of the vibrating plate from the upper space increases, so the pressure in the lower space conversely drops. The lower space communicates with the ambient atmosphere via a vent, and accordingly a part of the air in the ambient atmosphere near the vent is drawn into the lower space due to the drop in pressure. Alternately, when the vibrating plate is displaced downwards for example, the volume of the upper space in the chamber increases, so the pressure in the upper space conversely drops. The upper space communicates with the ambient atmosphere via the vent, and accordingly a part of the air in the ambient atmosphere near the vent is drawn into the lower space due to the drop in pressure. The volume of the lower space on the other side of the vibrating plate from the upper space is reduced, so the pressure in the lower space rises. The lower space communicates with the ambient atmosphere via the vent, and accordingly a part of the air within the upper space is externally discharged. Driving of the vibrating plate is performed by electromagnetic driving, for example. Such reciprocal action of the vibrating plate cyclically repeats the action of the air within the chamber being discharged into the ambient atmosphere, and the action of air from the ambient atmosphere being sucked into the chamber. Blowing a pulsating flow of air inducted by such cyclical reciprocal actions of the vibrating plate on heat sources such as the radiating fins (heat sink) effectively disrupts the thermal boundary layer at the surface of the radiating fins, and consequently the radiating fins are effectively cooled.    Patent Document 1 Japanese Unexamined Patent Application Publication No. 2000-223871 (FIG. 2)    Patent Document 2 Japanese Unexamined Patent Application Publication No. 2000-114760 (FIG. 1)    Patent Document 3 Japanese Unexamined Patent Application Publication No. 2-213200 (FIGS. 1 and 3)    Patent Document 4 Japanese Unexamined Patent Application Publication No. 3-116961 (FIGS. 3 and 8)